Ecology of fishes in a high-latitude, turbid river with implications for the impacts of hydrokinetic devices

Abstract

Hydrokinetic devices generate electricity by capturing kinetic energy from flowing water as it moves across or through a rotor, without impounding or diverting the water source. The Tanana River in Alaska, a turbid glacial system, has been selected as a pilot location to evaluate the effects of such a device on fish communities that are highly valued by subsistence, sport, and commercial users. The basic ecology and habitat use of fishes in turbid glacial systems are poorly understood; therefore it is necessary to study the species composition of the fish community and the spatial and temporal patterns of mainstem river use by these fishes to evaluate impacts of a hydrokinetic device. In this document, we provide an overview of existing knowledge of fish ecology in the Tanana River and impacts of hydrokinetic devices on fishes in other river systems. Seventeen fish species are known to inhabit the Tanana River and several may utilize the deepest and fastest section of the channel, the probable deployment location for the hydrokinetic device, as a seasonal migration corridor. Previous studies in clearwater river systems indicate that mortality and injury rates from turbine passage are low. However, the results from these studies may not apply to the Tanana River because of its distinctive physical properties. To rectify this shortcoming, a conceptual framework for a comprehensive fish ecology study is recommended to determine the impacts of hydrokinetic devices on fishes in turbid, glacial rivers.

Laboratory Experiments on the Effects of Blade Strike from Hydrokinetic Energy Technologies on Larval and Juvenile Freshwater Fishes

“…However, for most of the proposed HK turbine designs the rotors are projected to operate a lower RPM (revolutions per minute) than observed from conventional reaction turbines; the associated shear stress and pressure changes are expected to be lower and pose a smaller threat to fish survival (DOE 2009). Only a limited number of studies have been conducted to examine the risk of blade strike from hydrokinetic technologies to fish , Normandeau et al 2009, Seitz et al 2011, EPRI 2011; the survival of drifting or weakly swimming fish (especially early life stages) that encounter rotor blades from hydrokinetic (HK) devices is currently unknown.…”

Evaluation of Behavior and Survival of Fish Exposed to an Axial‐Flow Hydrokinetic Turbine

“…The diversity of HK designs implies a diversity of environmental impacts ( Cada et al 2007, but a potential impact common to most designs is the risk of blade strike to aquatic organisms (Wilson et al 2007). Only a limited number of studies have examined the risk of blade strike that HK technologies pose to freshwater fish (Turnpenny et al 1992;NAI 2009;Amaral et al 2011;Seitz et al 2011;Castro-Santos and Haro 2015), and the probabilities of blade encounter and turbine rotor passage survival are unknown for most species of fish. One study (EPRI 2011b) suggested that HK turbines present less harsh physical conditions to entrained fish than conventional hydropower turbines.…”

Hydrokinetic Micro-Power Generation in Small Rivers - a New Approach

“…It was seen that the new turbine operates in average 1117h and generates 420 kWh in a year whereas the rotating turbine just operates 41h and generates 80kWh. Due to their small size hydrokinetic turbines do not harm fish, which is a large advantage compared to the run-off river barrage power plants [3,10].…”